Method for producing fluorinated organic compounds

ABSTRACT

A method for preparing fluorinated organic compounds comprising contacting hydrogen fluoride with at least one compound of formula I:
 
CX 3 CXYCH 3   I
 
where each X is independently Cl, I or Br, and each Y is independently H or F, said contacting step being carried out under conditions effective to produce a compound of formula II
 
CF 3 CZCH 2   II
 
where Z is Cl, I, Br, or F.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is claiming the priority benefit of U.S. ProvisionalApplication No. 60/733,444 filed Nov. 3, 2005 and of U.S. ProvisionalApplication No. 60/733,383 filed Nov. 3, 2005. This application is alsois a Continuation-in-Part of U.S. patent application Ser. No.11/118,503, (pending) filed on Apr. 29, 2005, which in turn claims thepriority benefit of U.S. Provisional Patent Application Nos. 60/567,427and 60/567,425 filed Apr. 16, 2004.

This application is also a Continuation-in-Part of U.S. patentapplication Ser. No. 11/118,504, (pending) filed on Apr. 29, 2005, whichin turn claims the priority benefit of U.S. Provisional PatentApplication Nos. 60/567,426 and 60/567,429 filed Apr. 16, 2004.

This application is also a Continuation-in-Part of U.S. patentapplication Ser. No. 11/118,530, (pending) filed on Apr. 29, 2005, whichin turn claims the priority benefit of U.S. Provisional PatentApplication No. 60/567,428.

The disclosures of each of the above-mentioned applications areincorporated herein by reference. Also incorporated herein by referenceare the following U.S. Applications 60/733,378; 60/733,355; 60/733,383;60/733,377 and 60/733,379, each of which was filed on Nov. 3, 2005.

BACKGROUND

(1) Field of the Invention

This invention relates to novel methods for preparing fluorinatedorganic compounds, and more particularly to methods of producingfluorinated olefins.

(2) Description of Related Art

Hydrofluorocarbons (HFC's), in particular hydrofluoroalkenes such astetrafluoropropenes (including 2,3,3,3-tetrafluoro-1-propene(HFO-1234yf)) have been disclosed to be effective refrigerants, fireextinguishants, heat transfer media, propellants, foaming agents,blowing agents, gaseous dielectrics, sterilant carriers, polymerizationmedia, particulate removal fluids, carrier fluids, buffing abrasiveagents, displacement drying agents and power cycle working fluids.Unlike chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs),both of which potentially damage the Earth's ozone layer, HFCs do notcontain chlorine and thus pose no threat to the ozone layer.

Several methods of preparing hydrofluoroalkanes are known. For example,U.S. Pat. No. 4,900,874 (Ihara et al) describes a method of makingfluorine containing olefins by contacting hydrogen gas with fluorinatedalcohols. U.S. Pat. No. 2,931,840 (Marquis) describes a method of makingfluorine containing olefins by pyrolysis of methyl chloride andtetrafluoroethylene or chlorodifluoromethane. The preparation ofHFO-1234yf from trifluoroacetylacetone and sulfur tetrafluoride has beendescribed. See Banks, et al., Journal of Fluorine Chemistry, Vol. 82,Iss. 2, p. 171-174 (1997). Also, U.S. Pat. No. 5,162,594 (Krespan)discloses a process wherein tetrafluoroethylene is reacted with anotherfluorinated ethylene in the liquid phase to produce a polyfluoroolefinproduct.

Notwithstanding prior teachings, applicants have come to appreciate acontinuing need for methods of efficiently preparing certainhydrofluorocarbons, particularly tetrafluorpropenes such as HFO-1234yf.

SUMMARY OF THE INVENTION

Applicants have developed methods for producing fluorinated organiccompounds, including hydrofluoropropenes, which preferably comprisescontacting at least one compound of the formula (X_(a)Y_(1-a))F with atleast one compound of formula (I):CX₃CXYCH₃  (I)where each X is independently Cl, I or Br, each Y is independently H orF and a is 0 or 1.

The preferred contacting step of the present invention is carried outunder conditions effective to produce a compound of formula (II)CF₃CZ═CH₂  (II)where Z is Cl, I, Br, or F.In certain preferred embodiments the contacting step produces a reactionproduct comprising tetrafluoropropene, and in particular2,3,3,3-tetrafluoro-1-propene (HFO-1234yf).

The contacting step preferably comprises reacting a compound of formula(I) with at least one compound of the formula (X_(a)Y_(1-a))F, such asHF, in the gas phase in the presence of a catalyst. In preferredembodiments, the conversion of the compound of formula I in the reactionis from about 70% to about 100%. In certain embodiments, including thosewhich produce conversion levels as indicated herein, the selectivity ofthe reaction to tetrafluoropropene, and to HFO-1234yf in particular, isfrom about 5 to about 40%. In certain preferred embodiments the reactionproduct also contains a trifluor-monochloropropene, particularly2-chloro, 3,3,3,trifluoro-1-propoene (HFO-1233xf) with a selectivity offrom about 50% to about 90%.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

One beneficial aspect of the present invention is that it enables theproduction of desirable fluroolefins, preferably C3 fluoroolefins, fromrelatively low cost and readily obtainable starting materials. Morespecifically, certain preferred embodiments of the present inventioninvolve producing the desired C3 fluoroolefin from C3 olefin's, such aspropylene. Propylene is in many embodiments an advantageous startingmaterial because it is relatively inexpensive, is relatively easy tohandle, and is generally readily available in commercial quantities.

Thus, in certain embodiments the present methods include the step ofreacting C3 olefin, such as propylene, with a halogenating agent (suchas ClF or HF) under conditions effective to produce a compound offormula (III)CH_(3-n)X_(n)CXYCH₃  (III)where n is 0, 1 or 2. This reaction is sometimes referred to herein forconvenience but not necessarily by way of limitation, as a halogenaddition reaction.

Preferably, the compound of formula (III) is then reacted, preferably ina photo-chlorination reaction, to produce a reaction product containingat least one compound of formula (I) as described above. Preferably theformula (I) compound is then exposed to reaction conditions, which aresometimes referred to herein for convenience, but not necessarily by wayof limitation, as fluorination to produce a reaction product containingone or more of the desired fluorolefins. Preferred aspects of each ofthese preferred steps is described below, with the titles used asheadings for these steps being used for convenience but not necessarilyby way of limitation.

A. Reaction of C3 Olefin with Halogenating Agent

In preferred embodiments, a compound of formula (IV)CH_(n)X_(3-n)CHC═CH₂  (IV)is contacted under reaction conditions with a compound of formulaX_(m)Y_(2-m) wherein X, Y are as defined above, provided that thecompound is not H₂, and m is 0, 1, or 2, to produce a compound offormula (III), namely, CH_(n)X_(3-n)CXYCH₃ where n is 0, 1 or 2. Inpreferred embodiments, the compound of formula (IV) is propylene (n is 3and X is H) and the compound of formula X_(m)Y_(2-m) is one or more ofClF, Cl₂, F₂ and HF, preferably one or more of ClF, Cl₂, and HF. Thecompound X_(m)Y_(2-m), and compounds which perform a similar function inthe present reactions, are referred to herein as halogenation agents.

In certain preferred embodiments, the contacting step comprisescontacting, (preferably by introducing into a reactor) the compounds inan halogenation agent:formula (IV) mole ratio of from about 1:1 to about4:1, and even more preferably of from about 2:1 to about 4:1. Inpreferred embodiments in which the compound of X_(m)Y_(2-m) comprises HFand the formula (IV) compound comprises propylene, the HF:propylene moleratio of the feeds to the reactor are from about 1:1 to about 10:1 andeven more preferably from about 2:1 to about 4:1. In preferredembodiments in which the compound of X_(m)Y_(2-m) comprises CIF (X isCl, Y is F, and m is 1) and the formula (IV) compound comprisespropylene, the ClF:propylene mole ratio of the feeds to the reactor arefrom about 10 to about 0.1 and even more preferably from about 1 toabout 0.2. In preferred embodiments in which the compound ofX_(m)Y_(2-m) comprises Cl₂ (m is 2 and X is Cl) and the formula (IV)compound comprises propylene, the Cl₂:propylene mole ratio of the feedsto the reactor are from about 5 to about 0.1 and even more preferablyfrom about 1 to about 0.2.

This reaction step can be carried out in the liquid phase and/or in thegas phase, and it is contemplated that the reaction can be carried outbatch wise, continuous, or a combination of these.

1. Liquid Phase Halogen Addition Reactions

Although not necessarily preferred, certain embodiments of the presentinvention (particularly when the X_(m)Y_(2-m) compound is ClF, HF orCl₂, or combinations of two or more of these) involve relatively lowtemperature reactions in which at least the organic reactant(s) arecharged to the reactor as liquids, with the reactor preferablymaintained at a temperature of from about −90° C. to about −50° C., andat least a portion of the reaction is carried in the liquid phase (thenormal boiling point H_(n)X_(3-n) of the preferred reactant propylene is−47.8° C.). However, it is contemplated that at least some portion ofthe reaction product may be produced and/or removed from the reactionmixture in such embodiments as a gaseous material.

For those preferred embodiments which utilize ClF as a reactant, it issometimes preferred to provide ClF, preferably in situ, by theliquid-phase reaction of HF and Cl₂ in the presence of catalyst,preferably a transition metal catalyst, and even more preferably atransition metal halide catalysts such as FeCl3, TaCl5, TiCl4, SbCl5,SbCl3, and CrCl3, SbF3, SbF5, AlF3, and CrF3, and combinations of two ormore of these. In certain preferred embodiments, therefore, the presenthalogenation step comprises contacting CH3CH═CH2, HF and Cl2 in thepresence of a metal catalyst, preferably a metal chloride salt,preferably with addition of kinetic energy to provide a substantiallyuniform reaction mixture (such as stirring), under conditions effectiveto form a reaction product comprising the desired compound of formula(III).

In certain preferred embodiments, the reaction is carried out at atemperature of from about −90° C. to about −50° C., more preferably fromabout −80° C. to about −70° C., under conditions effective to achieve apercentage conversion of at least about 70%, more preferably at leastabout 90%, and even more preferably at least about 100% of the compoundof formula (IV). Preferably, the reaction conditions are effective toachieve a percentage selectivity to compounds of formula (III), andpreferably 2-fuoropropane, of at least about 50%, more preferably atleast about 75%, and even more preferably at least about 95%. In certainpreferred embodiments a selectivity of about 98% or greater is achieved.

As used herein, the term “percentage conversion” with respect to areactant refers to the moles reacted in the reaction process divided bythe moles of reactant in the feed to the process multiplied by 100.

As used herein, the term “percentage selectivity” with respect to anorganic reaction product refers to the ratio of the moles of thatreaction product to the total of the remaining organic reaction productsmultiplied by 100.

In certain preferred embodiments the reaction time for the preferredliquid phase halogenation reaction is from about 1 to about 3 hours. Thereaction product in preferred embodiments includes one or more ofCH₃CHFCH₂Cl, CH₃CHClCH₂CI, CH₃CHCICH₂Cl, and/or CH₃CHFCH₃. In preferredembodiments, the reaction product comprises from about 40 wt. % to about75 wt. % CH₃CHFCH₂Cl, from about 5 to about 35 wt. % CH₃CHClCH₂CI, fromabout 5 to about 15 wt % CH₃CHCICH₂Cl, and less than about 5% CH₃CHFCH₃.

It will be appreciated that many alternatives for the provision of ClFin accordance with this preferred step of the present invention areavailable and within the scope hereof. By way of example, the reactantClF may be provided in certain embodiments simply by purchasing theneeded quantity of the material in the appropriate form. In otherpreferred embodiments, it is desirable to provide the ClF by conductinga liquid-phase Reaction of HF and Cl₂, preferably in the presence oftransition metal halide such as SbF₅. Such reactions, especially singlestage reactions, can be achieved using any equipment and conditionsknown and available in the art for such types of reactions, preferablyat a temperature of from about −50° C. to −90° C., and even morepreferably the reaction temperature is maintained at a temperature offrom about −65° C. to about −85° C.

In certain embodiments, a two stage reaction may be used, with the firststage being a gas phase reaction and the second stage being a liquidphase reaction. In such embodiments the ClF produced in this firstreaction stage, and/or from other sources, is preferably then charged toa second reaction vessel or to a second region of the same vessel,preferably a second autoclave, where it is contacted with a compound offormula (IV), such as propylene, at a temperature as specified above,preferably at about −75° C., and preferably under conditions capable ofproviding selectivity to a compound of formula (III0, preferablyCH₃CHFCH₂CI, of at least about 60% and up to about 75% or greater.

2. Gas/Liquid Phase Halogen Addition Reactions

Although not necessarily preferred, the formation of a compound offormula III may also be carried out at least partially in a gas phasereaction, preferably in the presence of a catalyst. For example, highconversion and selectivity can be achieved in some embodiments by firstreacting HF and Cl₂ in a liquid phase, and preferably in a continuousliquid phase reaction, by charging the reactor with a catalyst,preferably a transition metal halide such as SbF₅ and conducting thereaction at a temperature of from about −50° C. to 50° C. to produceClF. In such embodiments it is preferred to introduce the ClF producedin the gas phase, together with a compound of formula (IV), into aliquid phase reactor, generally in accordance with the conditionsdescribed above, to produce a compound of formula (III), preferably at aselectivity to CH₃CHFCH₂CI of at least about 60%, and even morepreferably at least about 70%.

3. Preferred Gas Phase Halogenation Reactions

For certain preferred embodiments, particularly those preferredembodiments which utilize HF as a reactant, it is preferred to provide acompound of formula (III) by a gas-phase Reaction of HF and a compoundof formula (IV) in the presence of catalyst, preferably a transitionmetal catalyst, and even more preferably a transition metal halidecatalysts such as FeCl₃, TaCl₅, TiCl₄, SbCl₅, SbCl₃, and CrCl₃, SbF₃,SbF₅, AlF₃, and CrF₃, and combinations of two or more of these. Incertain preferred embodiments, therefore, the preferred halogenationstep comprises contacting CH₃CH═CH₂, preferably an iron based catalyst,and even more preferable an iron chloride catalyst, and maintaining thereactor temperature at from about 20° C. to about 100° C., morepreferably from about 25° C. to about 35° C., with a preferred reactorpressure of from about 15 to about 200 psia, and even more preferablyfrom about 20 to about 100 psia. In such preferred embodiments HF ispreferably charged to the reactor, preferably as a liquid (for exampleby maintaining the vessel containing the HF under pressure, such as 45psig of N₂ head space pressure) and the compound of formula (IV) ischarged to the reactor, preferably as a gas. In such embodiments theconversion of the formula (IV) compound, particularly propylene, ispreferably at least about 40%, more preferably at least about 80%, andselectivity to compounds of formula (III), particularly 2-fluoropropane,is preferably at least about 40%, more preferably at least about 60%,more preferably at least about 80%, and in certain embodiments at leastabout 90%. In certain preferred embodiments selectivity of about 95% ispreferred. Examples of other catalysts that may be used in this aspectof the invention include carbon, carbon nanotubes, SbCl₅C, SbF₅/C,FeCI₃, CrF₃, Cr-oxyfluoride, and Cr₂03.

B. Chlorination of the Compound of Formula III

According to preferred aspects of this invention, a compound of formula(III), preferably but not necessarily produced in accordance with theprocedures described above, is chlorinated to produce a compound offormula (I), namely, CX₃CXYCH₃ where each X is independently Cl, I orBr, and each Y is independently H or F. In its broad aspects, thepreferred chlorination step is amenable to a large number of specificprocessing condition and steps in accordance with the teachingscontained herein, and all such variations are within the broad scope ofthe present invention. It is particularly preferred, however, that thechlorination step comprise photochlorination. Thus, the preferredreaction step comprises exposing the reactants, preferably in a liquidphase, to ultraviolet radiation, preferably in the range of from about200 to about 400 nm. The chlorination agent preferably compriseschlorine gas, either neat or preferably with a diluent such as nitrogen.A chorination catalyst, such as V₂O₅, Zeolites, and Au/Ti0₂ catalyst,may be used in certain embodiments. The reaction is preferably carriedout a temperature of from about −20° C. to about 200° C., and even morepreferably from about 25° C. to about 120° C. for a time of from about 5seconds to about 5 hours, more preferably from about 15 seconds to about30 min. The reaction product, which comprises a compound of formula (I),may then optionally be subject to one or more separation steps, such asdistillation, to remove unwanted byproducts and produce a streamrelatively concentrated in compounds of the formula (I).

C. Chlorination of the Compound of Formula II

The methods of the present invention preferably comprise reacting acompound of formula (I) with a fluorinating agent to produce afluorolefin, preferably a C3 fluorolefin, more preferably a compound offormula (II), and even more preferably tetrafluoropropene. Thispreferred reaction step may be described, by way of illustration but notnecessarily by way of limitation, by the following reaction equation inconnection with embodiments in which the compound of formula (I) istetrafluormonochloropropane and the fluorinating agent is hydrogenfluoride:CCI₃CFClCH₃+3HF→CF₃CF═CH₂+HCl

This aspect of the present invention is sometimes referred to herein asa fluorination reaction. In many aspect of such preferred embodiments,CF₃CCl═CH₂ (HFO-1233xf) is also produced in the reaction.

It is contemplated that this reaction step may be preformed using a widevariety of process parameters and process conditions in view of theoverall teachings contained herein. For example, it is contemplated thatcertain embodiments may comprise a liquid phase, non-catalytic reaction.However, it is generally preferred that this reaction step comprise agas phase catalyzed reaction, preferably a metal catalyst, and even morepreferably one or more transition metal-based catalysts (including incertain preferred embodiments transition metal halide catalysts), suchas FeCl₃, chromiumoxyfluoride, Ni (including Ni mesh), NiCl₂, CrF₃.Other catalysts include carbon-based catalysts, antimony-based catalysts(such as Sb/Cl₅), aluminum-based catalyst (such as AlF₃ and AlO₃). Manyother catalysts may be used, including palladium-based catalyst,platinum-based catalysts, Rhodium-based catalysts and ruthenium-basedcatalysts. Of course, two or more any of these catalysts, or othercatalysts not named here, may be used in combination.

In general it is preferred that the catalysts are pretreated byfluorination prior to use. In preferred embodiments, fluorination of thecatalysts comprises exposing the catalyst to a stream of HF at aboutreaction temperature and pressure.

In certain preferred embodiments, the present step of fluorinating acompound of formula I to produce a compound of formula II comprisescontacting a the formula I compound with a fluorinating agent,preferably under conditions effective to provide a formula I conversionof at least about 10%, more preferably at least about 55%, and even morepreferably at least about 70%. In certain preferred embodiments theconversion is at least about 90%, and more preferably about 100%.Furthermore, in certain preferred embodiments, the present step offluorinating a compound of formula I to produce a compound of formula IIis conducted under conditions effective to provide a formula IIselectivity of at least about 5%, more preferably at least about 20%,more preferably at least about 50%, and even more preferably at leastabout 90%. In embodiments in which the compound of formula I comprisesCCl₃CFClCH₃ (HCFC-241bb), the selectivity to HFO-1234yf is at leastabout 5%, more preferably at least about 10%, more preferably at leastabout 50% or higher, and the selectivity to HFO-1233xf is at least about5%, more preferably from about 30% to about 70%, and even morepreferably from about 40% to about 60%.

EXAMPLES

Additional features of the present invention are provided in thefollowing examples, which should not be construed as limiting the claimsin any way.

Examples 1-24

These examples illustrate gas phase fluorination-dehydrohalogenation ofCCI₃CFClCH₃ (241bb) to CF₃CCl═CH₂ (12334) and CF₃CF═CH₂(1234yf). A22-inch (½-inch diameter) Monel tube reactor is charged with 120 cc ofcatalyst, as specified in Table I below. All catalysts are fluorinatedfor 6 h with 80 glh of HF at reaction temperature under 20 psigpressure. The reactor is mounted inside a heater with three zones (top,middle and bottom). The reactor temperature is monitored using a 5-pointthermocouples kept at the middle inside of the reactor. The inlet of thereactor is connected to a pre-heater, which is kept at about 300° C. byelectrical heating. Liquid HF is fed from a cylinder into the pre-heaterthrough a needle valve, liquid mass-flow meter, and a control valve at aconstant flow of 1-1000 g/h. The HF cylinder is kept at a constantpressure of about 40 psig by applying anhydrous N₂ gas pressure into thecylinder head space. 10-120 g/h of organic compound of formula I(HCFC-241bb) is fed from a cylinder kept at about 145° C. through aregulator, needle valve, and a gas mass-flow-meter. The compound offormula I is also fed time to time as liquid at 120° C. from a cylinderinto the pre-heater through a needle valve, liquid mass-flow meter, anda control valve at a constant flow of 50-150 g/h. The organic line fromthe cylinder to the pre-heater is kept at 265° C. by wrapping withconstant temperature heat trace and electrical heating. All feedcylinders are mounted on scales to monitor their weight by difference.The reactions are run at a constant reactor pressure of about 0-100 psigby controlling the flow of reactor exit gases by another control valve.The gases exiting the reactor are analyzed by on-line GC and GC/MSconnected through a hotbox valve arrangement to prevent condensation.The product was collected by flowing the reactor exit gases through a20-60 wt % aq. KOH scrubber solution and then trapping the exit gasesfrom the scrubber into a cylinder kept in dry ice or liquid N₂. Theproducts were then isolated by distillation. The results are shown inTable I below.

TABLE 1 CCl₃CFCICH₃ + 3HF → CF₃CF═CH₂ + HCl % % % % ConversionSelectivity Selectivity Selectivity Example#/Catalyst T, C of 241bb to1234yf to 1233xf 1234yf/1233xf Example 1/Chromium 250 56 1 12 0.08Oxoxyfluoride Example 2/(Plant 320 92 7 85 0.08 Catalyst) Example3/(Plant 350 96 8 69 0.11 Catalyst) Example 4/(Plant 375 100 12 63 0.19Catalyst) Example 5/4-6 wt % 50 Plugged FeCl3/C Example 6/(NORIT- 100Plugged RFC-3) Example 7 120 100 14 57 0.25 Example 8 150 100 14 61 0.23Example 9 200 100 11 54 0.2 Example 10 220 100 9 43 0.2 Example11/Carbon 300 56 11 26 0.42 Example 12/Carbon 400 71 9 17 0.53 Example13/Carbon 500 89 5 14 0.36 Example 14/Ni-mesh 250 42 7 29 0.24 Example15/Ni-mesh 350 84 10 62 0.16 Example 16/Ni-mesh 425 100 14 53 0.26Example 17/25 wt % 110@50 psig 100 18 59 0.3 SbCls/C Example 18/25 wt %120@50 psig 100 21 49 0.42 SbCls/C Example 19/1.4 wt % 250 NiC12/Al2O3Example 20/1.4 wt % 320 92 14 62 0.22 NiC12/Al2O3 Example 21/1.4 wt %350 NiC12/Al2O3 Example 22/1.4 wt % 350 100 6 52 0.12 Ni/Al203 Example23/AlF3 150 82 0 8 0 Example 24/CrF3 200 89 2 11 0.18

In addition to the products identified in the table, other compoundsproduced in the reaction are 1,1,1-trifluoroethane (143a),3-chloro-2,2,3,3-tetrafluoropropane(244cc),3,3-dichloro-2,2,3-trifluoropropane(243cc),I-propene-1,1-dichloro-2-fluoro, 2,3,3-trichloro-2-fluoropropane(251bb),1-chloro-3,3,3-trifluoro-1-propene (1233zd), 3,3,3-trifluoro-1-propene(1243zf),1,1-dichloro-2-fluoro-1-propene,2,3,3-trichloro-2-fluoropropane,dichlorodifluoropropene, and carbon black.

Example 25

This example illustrates addition of F₂ to CH₃CH═CH₂ in a liquid phasereaction, which is illustrated by the following reaction scheme:CH₃CHCl₂+F₂→CH₃CHFCH₂F

About 1-100 wt % F₂ in nitrogen is bubbled through 125 g of liquidpropylene in a stirred Hastrelloy C reactor at about −50° C. to −75° C.for about 1 hour in the presence of HF as the solvent. A 1 gallon Parrreactor is first charged with a relatively inert solvent, HF, to helpwith heat transfer and dilution of the organic. Then 125 grams ofpropylene are added batch wise to the reactor. The reaction mixture iscontinuously mixed and cooled to the desired temperature. Then the F₂feed (1 wt %), diluted with N2 (99 wt %), is introduced continuouslydirectly into the reaction mixture through a dip tube until about 90% ofthe stoichiometric amount needed to convert all the propylene that isadded. The reactor temperature and pressure are controlled automaticallyat the desired set points of between −50 to −75° C. and a constantpressure of 40 psig. The temperatures are chosen to minimize the amountof propylene that would exit the reactor with the N₂ diluent. The gasesexiting the reactor are passed through a caustic scrubber carboy and anactivated alumina column to remove acidity, then a dri-rite column toremove moisture, and finally the organic is collected in a DIT. When thedesired amount of F₂ is added the reaction liquid is sampled. The sampleis absorbed in H₂O and the organic is recovered by phase separation. Theorganic is then analyzed by GC and GC/MS. The remaining material in thereactor is boiled off through the scrubbing system and the organic iscollected in the DIT and analyzed by GC and GC/MS. The analyses are usedto determine that the reaction has an overall selectivity to CH₃CHFCH₂Fof about 36-45%.

Example 26

This example illustrates addition of F₂ to CH₃CH═CH₂ in a gas phasereaction, which is illustrated by the following reaction scheme:CH₃CHCl₂+F₂→CH₃CHFCH₂F

The same apparatus as described in Example 25 is used, except thatgaseous propylene and 1% F2 (99% dilution w/N2) are fed into the Parrreactor via a common dip tube. Propylene is fed at a 50% stoichiometricexcess. The reactor is kept at 70° C. and at atmospheric pressure. Thereactor effluent is passed through a DIT, which collected most of theorganic. Only a couple of grams of vapor are left in the Parr reactor atthe end of the experiment. GC analysis of the material indicated about10% conversion of the propylene. The selectivity to CH₃CHFCH₂F is about32% based on GC area %.

Example 27

This example illustrates addition of F2 to CH3CH═CH2 in a gas phasereaction under the same conditions as Example 26, except the reaction isperformed at higher temperature of about 0 to −20° C. A yield of about10% CF₃CHFCH₂F is obtained, which is then transformed to HFO-1234yf with100% selectivity in the next step by reacting with 20% KOH solution inthe presence of 18-crown ether as the phase-transfer catalyst at about55° C. using a 300 ml autoclave.

Example 28

This example illustrates addition of fluorine to CH₃CH═CH₂ in a gasphase reaction, which is illustrated by the following reaction scheme:CH₃CHCl₂+HF→CH₃CHFCH₃In a gas-phase reaction a Monel tube reactor was charged with 1909 cc of4-6-wt % FeCl₃/C (NORIT-RFC 3, commercial catalyst from NORIT NEDERLANDB.V.). The reactor was mounted in a constant temperature sand-bath with40-50 mI/min of air flowing through the sand-bath. The sand-bath setpoint was set at 28° C. during the reaction. The inlet of the reactorwas connected to a pre-heater which was kept at 106° C. by supplying 30psig steam through the jacket. The liquid-HF was fed from a cylinderinto the pre-heater through a positive displacement pump and kept at aconstant flow of 15.88 mol/h (318 g/h) by controlling the flow with aresearch control valve. The HF cylinder was kept at a constant pressureof 30-40 psig by applying anhydrous N₂ gas pressure into the cylinderhead space. A 5.4 mol/h (227 g/h) of propylene is fed as a gas from acylinder through a regulator, needle valve, and flow controller directlyinto the reactor inlet at a point just after the pre-heater. HF andPropylene cylinders were mounted on two different scales to monitortheir weight by difference. The reactions were run at a constant reactorpressure of 25 psig by controlling the flow of reactor exit gases byanother research control valve. The mole ratio of HF to Propylene waskept at 2.94 with a contact time of 33 sec. The exit gases coming out ofthe reactor were analyzed by an on-line GC and GCMS connected through ahotbox valve arrangements to prevent condensation. The conversion ofPropylene was almost 100% and the selectivity to 2-Fluoropropane was98%. The reaction was performed continuously over 4 days period and thecatalyst did not loose any activity. The product was collected byflowing the reactor exit gases through a 20-60 wt % aq. KOH scrubbersolution and then trapping them in a cylinder kept inside dry ice orliquid N₂.

Examples 29-42

This example illustrates the chlorination of 2-fluoropropane (CH₃CHFCH3)to CCl3CFClCH3 (241bb) in a gas phase reaction, which is illustrated bythe following reaction scheme:CH₃CHFCH₃+4Cl_(2→(light))CCl₃CFClCH₃+4HCl

A 500 ml Pyrex reactor was placed inside a Rayonet photo chlorinator atroom temperature (25° C.). The reactor used in this study was aRAYONETModel-RPR-100 with standard operating temperature of 35° C. andstandard power consumption around 400 watts. The inside of the photochlorinator was equipped with 16 UV-lamps; the number of lamps could bevaried easily. The 2-Fluoropropane was fed into the reactor from acylinder kept at a constant water bath temperature of 35° C. through aregulator and mass-flowcontroller. Chlorine gas was fed from a cylinderthrough a regulator, needle valve, and a massflow-controller into thereactor. N₂ was used as the diluents, though the reaction proceeds wellwithout it from a cylinder, which was fed from a cylinder throughregulator and mass-flowcontroller. A fan at the bottom of the photochlorinator was kept on with a constant flow of N₂ to helped keeping thereactor at a constant temperature. This was because of fast dissipationof heat of reaction to avoid run-away reaction. The products that werehigh boiling liquids stayed inside the reactor collection section,collected and analyzed after the stipulated reaction time. The exitgases out of the reactor was analyzed by on-line GC which containsmainly unreacted 2-fluoropropane, N2 and mono-chlorinated products. Theliquid products thus obtained was then washed with water to remove HCland soluble Chlorine and then purified by distillation under vacuum. Theexperimental mp of 241bb is 98-101° C. and boiling is 139° C. The puritywas around 95-100%. The results are shown in Table 2 below.

TABLE 2 Photo chlorination of 2-Fluoropopane (R281ea) to CCl₃CFClCH₃(241bb) Mole Contact ratio % Sel. to FP, Cl₂, N₂, time, of Cl₂ % CCl₃CF% Overall Ex # Sccm sccm sccm sec to FP T, h Lamp Conversion CICH₃ sel.29 20 96 0 206 4.8 2 8 48 18 49 30 20 80 0 239 4 2 8 52 29 62 31 20 8050 159 4 1 8 54 38 71 32 20 80 100 120 4 1 8 46 19 63 33 20 120 50 126 61 8 75 35 69 34 20 150 50 108 7.5 1 8 34 19 81 35 20 20 76 206 1 1 8 2726 85 36 20 40 56 206 2 1 8 35 20 81 37 20 60 36 206 3 1 8 35 28 82 3820 80 16 206 4 1 8 42 32 74 39 20 96 0 206 4.8 1 8 50 42 73 40 20 96 0206 4.8 0.25 8 45 35 70 41 20 96 0 206 4.8 0.5 8 40 37 76 42 20 96 0 2064.8 0.75 8 54 41 71 FP is 2-Fluoropropane; sccm is standard cubiccentimeter per minute; total volume of the reactor in contact with thelight is 450 ml (Pyrex);Conversion is the ratio of moles of FP convertedto products to total moles of FP fed; Selectivity to CCl₃CFClCH₃ is theratio of moles of FP converted to CCl₃CFClCH₃ to total moles of FPreacted;Overall selectivity is the ratio of moles of FP converted toCH₃CFCICH₃, CICH₂CFCICH3, Cl₂CHCFCICH3, and CCl₃CFClCH₃ to total molesof FP reacted. There are total 16 lamps.The reactor is aBAYONET-Model-RPR-100, standard operating temperature 35° C. andstandard power consumption 400 watts.

Examples 43-72

This example illustrates the photochlorination of 2-fluoropropane(CH₃CHFCH₃) to CCl₃CFClCH₃ (241 bb) in a gas phase reaction as describedin Examples 29-42, except 4 parameters are varied, including flow ratesof Cl₂ and 2-Fluoropropane, time of irradiation, and number of lamps atroom temperature. The results are reported in Table 3 below:

TABLE 3 Photo chlorination of 2-Fluoropopane to CCl₃CFClCH₃ % Overallsel. Mole to mono-, di-, ratio % Sel. to tri-and Cl₂, 2-FP, Time, No ofN₂, Contact of Cl₂ % 2-FP CCl₃CF tetra-chloro Ex # Sccm sccm min lampssccm time, sec to 2-FP Conversion ClCH₃ compound S 43 80 40 20 4 25 1652 65 57 68 44 80 20 20 4 25 191 4 70 44 74 45 50 30 30 6 25 228 1.7 3154 67 46 50 30 30 6 25 228 1.7 31 54 67 47 20 20 20 4 25 367 1 54 24 9048 20 40 20 8 25 281 0.5 34 14 87 49 20 40 40 4 25 281 0.5 33 18 93 5080 40 40 8 25 281 0.5 54 48 57 51 80 40 20 8 25 165 2 100 55 61 52 20 4020 4 25 281 0.5 22 1.8 78 53 80 20 40 4 25 191 4 72 50 57 54 80 20 20 825 191 4 96 28 43 55 80 40 40 4 25 164 2 55 55 64 56 80 20 40 8 25 191 482 29 38 57 20 40 40 8 25 281 0.5 26 14 81 58 20 20 40 4 25 368 1 47 1585 59 50 30 30 6 25 228 1.7 37 49 62 60 50 30 30 6 25 228 1.7 37 49 6261 20 20 40 8 25 368 1 58 30 68 62 20 20 20 8 25 368 1 34 32 74 63 50 3010 6 25 228 1.7 90 48 67 64 110 30 30 6 25 145 3.7 61 52 63 65 50 50 306 25 191 1 30 54 67 66 50 10 30 6 25 281 5 100 3 27 67 0 30 30 6 25 5310 0 0 0 68 50 30 30 6 25 228 1.7 31 54 67 69 50 30 30 6 25 228 1.7 31 5467 70 50 30 30 10 25 228 1.7 58 44 52 71 50 30 30 2 25 228 1.7 68 56 7772 50 30 50 6 25 228 1.7 63 54 64

Having thus described a few particular embodiments of the invention,various alterations, modifications, and improvements will readily occurto those skilled in the art. Such alterations, modifications, andimprovements, as are made obvious by this disclosure, are intended to bepart of this description though not expressly stated herein, and areintended to be within the spirit and scope of the invention.Accordingly, the foregoing description is by way of example only, andnot limiting. The invention is limited only as defined in the followingclaims and equivalents thereto.

1. A method of preparing fluorinated organic compounds comprisingcontacting hydrogen fluoride with at least one compound of formula (I):CX₃CXYCH₃  (I) where each X is independently Cl, I or Br, and each Y isindependently H or F, said contacting step being carried out in the gasphase to produce a compound of formula (II)CF₃CZ═CH₂  (II) where Z is Cl, I, Br, or F.
 2. The method of claim 1wherein said compound of formula (I) is formed by chlorinating stepcomprising contacting a compound of formula (III)CH_(n)X_(3-n)CXYCH₃  (III) where each X is independently Cl, I or Br,each Y is independently H or F, and where n is 0, 1 or 2 with achlorinating agent.
 3. The method of claim 2 wherein said chlorinatingagent comprises chlorine gas.
 4. The method of claim 2 wherein saidchlorinating step is conducted in the presence of light.
 5. The methodof claim 4 wherein said light has a wavelength of from about 250 toabout 400 angstroms.
 6. The method of claim 2 wherein said chlorinatingstep is carried out at a temperature of from about 20° C. to about 50°C.
 7. The method of claim 2 wherein said chlorinating agent compriseschlorine gas and a diluent.
 8. The method of claim 2 wherein saidcompound of formula III comprises a compound of formula (IIIA)CH₃CXYCH₃  (IIIA).
 9. The method of claim 2 wherein said compound offormula III comprises a compound of formula (IIIB)CH₂ClCHFCH₃  (IIIB).
 10. The method of claim 2 wherein said compound offormula III comprises a compound of formula (IIIC)CH₂ClCHClCH₃  (IIIC).
 11. The method of claim 2 wherein said compound offormula III is formed by contacting propylene and/or a compound offormula (IV)CH_(n)X_(3-n)CHC═CH₂  (IV) with a compound of formula X_(m)Y_(2-m) whereeach X is independently Cl, I or Br, and each Y is independently H or F,and wherein m is 0, 1, or 2 and provided that the compound is not H₂.12. The method of claim 11 wherein said compound of formula X_(m)Y_(2-m)is HF.
 13. The method of claim 11 wherein said compound of formulaX_(m)Y_(2-m) is Cl₂.
 14. The method of claim 11 wherein said compound offormula X_(m)Y_(2-m) is ClF.
 15. The method of claim 11 wherein saidcompound of formula IV comprises propylene.
 16. The method of claim 15wherein said compound of formula X_(m)Y_(2-m) is selected from the groupconsisting of ClF, HF, Cl₂ and combinations of two or more of these. 17.The method of claim 16 wherein said compound of formula X_(m)Y_(2-m) isHF.
 18. The method of claim 17 wherein said step of contacting acompound of formula IV comprises conducting at least a portion of saidcontacting step at a temperature of from about 70° C. to about 100° C.19. The method of claim 17 wherein step of contacting a compound offormula IV comprises conducting at least a portion of said contactingstep at a pressure of from about 5 to about 150 psia.
 20. The method ofclaim 17 wherein said step of contacting a compound of formula IVcomprises conducting at least a portion of said contacting step in thegas phase.
 21. The method of claim 17 wherein said step of contacting acompound of formula IV comprises conducting at least a portion of saidcontacting step in the gas phase and in the presence of a catalyst. 22.The method of claim 21 wherein said catalyst comprises an iron-basedcatalyst.
 23. The method of claim 21 wherein said catalyst comprisesiron chloride.
 24. The method of claim 21 wherein said catalystcomprises from about 4 to about 6 percent by weight of iron (III)chloride on a carbon support.
 25. The method of claim 16 wherein saidcompound of formula X_(m)Y_(2-m) comprises ClF.
 26. The method of claim25 wherein said step of contacting a compound of formula IV comprisesconducting at least a portion of said contacting step at a temperatureof from about −95° C. to about −30° C.
 27. The method of claim 25wherein said step of contacting a compound of formula IV comprisesconducting at least a portion of said contacting step at a pressure offrom about 5 to about 150 psia.
 28. The method of claim 25 wherein saidstep of contacting a compound of formula IV comprises conducting atleast a portion of said contacting step in the liquid phase.
 29. Themethod of claim 1 wherein said contacting step comprises conducting atleast a portion of said contacting step at a temperature of from about100° C. to about 600° C.
 30. The method of claim 1 wherein saidcontacting step comprises conducting at least a portion of saidcontacting step at a pressure of from about 10 to about 120 psia. 31.The method of claim 1 wherein said contacting step comprises conductingat least a portion of said contacting step in the presence of acatalyst.
 32. The method of claim 31 wherein said catalyst comprisesnickel.
 33. The method of claim 31 wherein said catalyst comprises ironchloride.
 34. The method of claim 31 wherein said catalyst comprisesfrom about 4 to about 6 percent by weight of iron (III) chloride on acarbon support.